By virtue of KuPS not returning to action until the following day, Inter Turku knew that a second win in a row would take them three points clear at the top of the table.
Six minutes before the break, the visitors got the goal they craved, as Jasse Tuominen struck his first league goal since June, keeping his 25-yard free-kick low and catching out the goalkeeper. FC Inter had chances to kill the game off in the second half, though with Oulu having just one shot on goal in the match, one goal always looked like being enough.
A win by any margin against VPS will see KuPS reclaim first place, while three losses in a row keep Oulu bottom of the championship group.
It's one win and now a draw apiece in this season's Helsinki derbies, as Gnistan remained fourth, a point behind neighbours HJK. Ayo Obileye headed home a pinpoint cross midway through the first half to put the hosts ahead, but just two minutes later the ball fell kindly to Pyry Mentu who lashed home HJK's equaliser to share the spoils.
It's back-to-back draws for HJK, who are unbeaten in four, while Gnistan have drawn three of their previous four, yet are now seven unbeaten and five points clear of VPS in the race for Europe.
SJK have confirmed their Veikkausliiga survival and condemned at least one of Jaro and Mariehamn to relegation after coming from behind to beat their rivals in the survival battle. Mariehamn's great escape looked to be continuing when Arvid Bergvik put them ahead before the break, only for Kelwin to equalise midway through the second half.
Things got worse for the visitors when Foster Gyamfi was sent off with 10 minutes to play, and SJK took full advantage, as Aapo Bostrom scored the winner three minutes from time to take the Seinajoki side seven points clear with two games to go.
Mariehamn remain in the relegation play-off place, but now only on goal difference after Jaro picked up a second point in as many matches, as Valde Lofs scored an 89th-minute leveller away at Lahti, 80 minutes of play after Martim Augusto had put Lahti ahead.
Regardless of the Round 26 results, the Jaro vs Mariehamn match on the final day which side is automatically relegated. Lahti, meanwhile, stay seventh despite no wins in two.
Follow the final weeks of the Veikkausliiga season on Flashscore.